Re-texturing is part of the textile finishing process and is intended to impart to flock, slubbing, fabric, knitted goods or non-woven materials in particular such properties as feel, smoothness, anti-static properties and body as a result of which their appearance, marketability, effectiveness in use and processing qualities are improved.
The textile aids used for re-texturing can, for example, be applied onto textile fiber materials in a total immersion bath (exhaustion process). In the total immersion treatment, the textiles are wetted for a long period at a high wash-liquor ratio and then de-watered by squeezing, extraction or centrifuging. Compared to other types of treatment processes such as foularding, padding, doctoring or spraying, the total-immersion treatment has the advantage that the treatment times and temperatures can be chosen and varied at will.
Conventional smoothing/softening aids include condensation products prepared from a hydroxyalkyl polyamine and a fatty acid glyceride, along with amino-silicone compounds, which are used in the form of aqueous dispersions. It is also known that the higher the amine content in a smoothing/softening aid, the softer the finished product will feel. However, the presence of a high degree of amines in compounds such as these makes them susceptible to oxidative degradation, thus causing textiles treated therewith to become yellowed during application.
One solution to the oxidative degradation and concomitant yellowing encountered with amino-silicone softening aids has been to employ secondarily hindered amines-silicone compounds (hindered amine siloxanes). These types of compounds have a hindered amine light stabilizing molecule grafted onto a silicone backbone. Due to the presence of a highly hindered, secondary-amine, the possibility of oxidation of the amine is greatly reduced so that high energy levels would be required in order to de-stabilize the chemical structure and cause undesirable yellowing. Secondarily hindered amines of this type also provide free radical scavenging properties which further prevent oxidation and subsequent yellowing.
However, one problem associated with the use of these types of secondarily hindered amine siloxanes relates to their tendency to exist as highly viscous compositions which require the use of sophisticated and involved mixing apparatuses in order to formulate them into pumpable, low-viscosity liquids which can be easily introduced into an aqueous bath on demand.